Boiler



(No Model.}

BOILER.

Patented Mar. 11, 1899.

i UNITED STATES PATENT OFFICE.

THOMAS L. STURTEVANT, OF FRAMINGHAM, MASSACHUSETTS.

BOILER.

SPECIFICATION forming part of- Letters Patent No. 422,994, dated March 11f 1890.

Application filed October 23, 1889. Serial No. 328,483. (No model.)

To all whom, it may concern,.-

Be it known that I, THOMAS L. STURTEVAN T,

. a citizen of the'United States, residing at FravIO marked thereon, which form a of the valves in the blow-oft' tube.

mingham,in thecounty of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Boilers; andI do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference part of this specification.

This invention relates to improvements in boilers for steam-generating purposes, particularly that class termed porcupine/in which a series of water-legs are disposed eX- teriorly of the boiler-shell; and it consists of apparatus by which said water-legs, closed at one end, can be easily and instantaneously blown out or cleansed from any sediment or foreign bodies which may collect in the 'extremities thereof.

The drawings represent in Figure l a sectional end elevation of a boiler containing my improvements. Fig. 2 is a side View ofthe same. Fig. 3 is an enlarged section of on In boilers of the class above premised, generally styled porcupine, the water-legs closed at one end (the outer) have a defective circulation; but in the class herein shown the water-legs or projecting water-chambers proper contain a second tube termed a Field tube. My invention is particularly adapted to the blowing out or cleansing of said waterlegs without the removal of the end closing cap or plug.

In the accompanying drawings, A represents a boiler-shell circular in cross-section and provided with the customary longitudinal lines B, and further exteriorly furnished upon the lower half of its periphery with a series of radially-disposed pendent water-legs C C. These water-legs are furnished with an inner tube, often termed a Field tube; hence the water-legs proper are composed of an outer tube @,open at the end leading into the boiler and closed at the outer end with a plug or cap b, while a second tube c, axially within the tube a, but open at both ends, is supported c, less exposed to the fire, is maintained at a low'cr temperature; hence a natural circulation occurs, the water entering the Water-leg centrally through the tube c, and returning to the boiler by the way of the annular passage d, created by the two tubes non-contiguous. Necessarily, from the position of such water-legs, the sediment and deposits of all kinds tend to accumulate at the closed end of said water-legs, and usually it is customary to remove the end caps to free them from such material. My invention is to obviate this mode of proceeding, and I propose to blow out said water-legs simply by opening' a valve common to a series and employing the steam within the boiler to accomplish this result without removing the end caps. To this end I proceed as follows, it being understood that said water-legs are arranged in rows or series, generally extending nearly the entire length of the boilerupon its under portion; further, the water-legs of each row or series are connected and communicate with a common blow-off tube D, the inner ends of said tube c terminating in the said tube D. This latter is to be supplied with one or more automatic valves e, which normally are open to permit the water-legs to effect the same circulation as has heretofore been produced. This tube D connectswith a blow-off pipe F, which is controlled by a valve f.

The operation-of the several parts above enumerated is readily understood, as I shall now explain. The circulation within the boiler-the latter suitably provided with a heat-generating agency and after being subjected to its action--is as indicated by the arrows in broken lines, the cooler water within the tube D passing downward through the inner tube c, returning to the boiler by way of the outer tube a, thereby becoming heated and, as a consequence, rising upward to produce steam. As a result of the above action, a iiow of water is now induced from the boiler; such water entering the tube D through the valve or valves e, now open. This circulation continues until it becomes desirable to clean the water-legs. To accomplish this result the valve f in the blow-oftl pipe F is opened. Immediately the valves c close,

IOO

ally removes all sediment or deposits of foreign matter, which pass 'out with lthe escaping steam and water. By such an arrangement the Water-legs can be completely cleansed at any moment, and thedifficulty and labor of vremoving the closing-caps is overcome.

In connection with this style of boiler, which is peculiarly adapted for marine purposes, I propose to employ a perforated or foraminated plate G. The latter is intended to prevent the Water from rushing from one end of the boiler to the other, While at the same time steam or Water can readily pass,

` but in slower movement, therethrough. Said "plat-e is preferably to be located horizontally in the plane of normal Water-level, or therepresence of two Witnesses.

about, and is to extend the entire length of theboiler.

Vhat I desire to claim is- Y 1. The improvements in steam-boilers consisting of a boiler-shell having a Water-supply and steam-discharge, a Water-leg or projecting Water-chamber composed of tWo tubes, one within the other, and a blow-off tube, the latter interconnecting the inner tubes and adapted to discharge eXteriorly of the boiler, but provided with an automatically-operating stop-valve Within said boiler, the circulation in the Water-legs being reversed upon Opening of the blow-oit tube, substantially as herein specified.

2. The combination, with a boiler, its fireiues and ordinary operating parts, of a series .i of projecting Water-chambers, abloW-off tube provided with a series of automatic stopvalves, and a pipe from said blow-oit tube eX- teriorly of the boiler, all co-operat ing as herein stated. f

3. The combination, With' a boiler, of a se'- ries of tubes closed at one end, a series of tubes, one in each closed tube, but open' at fboth ends, and a blow-off tube connecting with a blow-off pipe, said blow-off tube having a curvature corresponding to the shape of the lower half of the boiler and being pro! vided with an automatic stop valve or valves, substantially as herein described.

In testimony whereof I afx iny'signature in THOS. L. STURTEVANT. Witnesses:

H. LoDGE, FRANCIS C. STANWooD. 

